Split relay locks



Dec. 13, 1955 w. R. BASTOW 2,727,189

SPLIT RELAY LOCKS Filed March 15, 1951 CONTROLLED CIRCUIT CONTROLLED C/IZCLJ/T INVENTOI? WENDELL f2. BAsTow T TO/ZNE Y United States Patent SPLIT RELAY LCKS Wendell R. Bastow, Natick, Mam, assignor to Raytheon Manufacturing Company, Newton, Mass., at corporation of Delaware Application March 15, 1951, Serial No. 215,720

3 Claims. (Cl. 317-149) This invention relates to a split relay lock circuit of the type that permits a relay to be energized by either of two signals and deenergized by the repetition of a predetermined one of the first two signals, or the occurrence of a third signal.

In various indication and control devices it is desirable to have one occurrence of either of two predetermined signals energize a relay and a second occurrence of a predetermined one of those signals, or the occurrence of a predetermined third signal, deenergize it. Other circuits have been devised for this purpose, but they are quite complicated and frequently involve the use of two or more sets of switching elements. The present invention requires only a quite simple circuit and one switching device other than the relay to be controlled. It also functions equally well on direct and alternating current signals.

Briefly, the apparatus of the invention comprises a relay having two operating coils wound so as to produce opposing magnetic fields controlling two normally open and two normally closed contacts, a holding contact and the contact in the circuit to be controlled. The coils of the relay are energized through the plate cathode circuit of a thyratron and two sets of contacts controlled by the relay. The normally closed one of these contacts connect the plate of the thyratron to a source of positive potential through one coil of the relay, and the normally open one of these sets of contacts connects the plate to positive through the other coil of the relay and a resistor. There is also a normally open set of holding contacts controlled by the relay completing the circuit from positive through the first-mentioned relay coil and a resistor to ground. The grid of the thyratron is connected to one signal input terminal directly, to a second signal input terminal over a normally closed set of contacts and to a third signal input terminal over a normally open set of contacts.

The grid of the thyratron is normally biased to cut-01f. The coils of the relay are each paralleled by a capacitor to retain energization during switching.

In operation, a signal appearing on the input terminal directly connected to the grid of the thyratron or the terminal connected to the grid through the second-mentioned set of normally closed contacts, if positive in polarity or the positive alternation of an alternating current signal, and if sulficiently strong, will overcome the negative bias and trigger the thyratron. Current will then flow through the thyratron and the upper half of the coil. The contacts controlled by the relay close, including that in the controlled circuit and the holding contact. This last contact is closed before the plate circuit of the thyratron is opened by the operation of the first-mentioned set of normally closed contacts. This holding contact keeps the first coil of the relay energized after the thyratron has been extinguished. The thyratron is then readied to be triggered by a signal appearing on the second or third input terminals now connected to its grid. When such a signal appears current flows through the second coil of the relay over a circuit including a resistor and the Id cathode-plate space of the thyratron. At this time, current is still flowing through the first coil by way of the holding contact. As these two coils are arranged to create opposite fluxes in their common core when energtized, their effects tend to cancel each other and the controlled contacts return to rest position.

The coil of a relay may be substituted for the grid of a thyratron if the signal energy is sufi'icient. A set of normally open contacts which are operated by this added coil may be substituted for the plate to cathode path of the thyratron.

The foregoing and other advantages, objects and features of the invention will be better understood from the following description taken in conjunction with the accompanying drawings, wherein:

Fig. 1 is a schematic of a circuit embodying the invention; and

Fig. 2 is a modification of this circuit.

In Fig. l the reference numeral 10 represents one coil of the relay which is connected at one end to the second coil 11 and to a terminal 12 of a source of positive potential. The coils 10 and 11 are wound on a core 13. Two sets of normally closed contacts 14 and 15, and four sets of normally open contacts 16, 17, 18 and 20, are arranged to be operated by the coils 1i! and 11 through magnetic action on the core 13 and extended operators 21 and 22 attached thereto. The set of normally closed contacts 14 is connected between the grid 23 of a grid-controlled gaseous discharge device or thyratron 24 and an input terminal 25. The grid 23 of the thyratron 24 is also connected to a second input terminal 26 directly and to a third input terminal 27 over the normally open set of contacts 16. The cathode 28 of this thyratron 24 is connected to ground through a source of potential 30. The plate 31 of the thyratron 24 is connected to a terminal 32 of the coil 10 over a normally closed set of contacts 15. The terminal 32 is also connected to ground through a normally open set of contacts 17 and a resistor 33. The plate 31 is also connected over a normally open set of contacts 18 and through a resistor 34 to a terminal 35 of the coil 11. Each coil 10 and 11 has a capacitor 36 and 37, respectively, connected across its terminals.

Before any signal is received, the thyratron 24 is biased to cut-ofi by the negative potential from source 3% between its cathode 2t; and its grid 23 and there is no current flowing through either coil it or 11 and all contacts are in their normal condition.

When a positive direct current signal or the positive alternation of an alternating current signal is received at either terminal 25 or 26, a positive potential is applied to the grid 23 or" the thyratron 24 directly from terminal 26 and over the normally closed contact 14 from terminal 25. If this signal is of sufficient strength to counteract the negative bias, the thyratron 24 is triggered and current flows through the thyratron 2d, the normally closed contact 15, and the coil 10.

When the coil 10 is energized it operates the contacts 14, 15, in, 17, 18 and 26. Contact 2% closes the controlled circuit. The contact 17 closes to complete the circuit from terminal 12, coil in, and resistor 33 to ground to hold the coil 14) energized when the normally closed set of contacts 15 break. Operation of contacts 14 and 1'6 also shifts the grid 23 of thyratron 24 from the input terminal 25 to input terminal 27 by opening the normally closed contacts 14 and closing the normally open contacts 16.

Now if a second positive pulse appears at input terminal 25, nothing will happen as the normally closed contact 14 is now open and this positive potential cannot reach the grid of the thyratron 24 to trigger it. If such a pulse appears at either terminal 26 or 27, the negative bias will be overcome and thyratron 24 will fire permitting the current to flow from terminal 12, through coil 11, resistor 34, normally open, now closed, contact 18, and the plate cathode space of the thyratron 24. Current is still flowing through coil because of the holding contact 17. As explained above, the coils 10 and 11 are wound and connected so as to develop equal opposing magnetic forces in the core 13 so that there is no net force exerted on the extended operators of the con tacts 14, 15, 16, 17, 18 and 20 when both coils are energized. As a result these contacts return to their normal position at this time.

This breaks contact 18 and extinguishes the thyratron 24 before making the contact 15. It also breaks the holding contact 17 and the controlled contact 21). The grid 23 is transferred from terminal 26 and 27 to terminals 25 and 26, the initial condition.

Thus a signal on terminal 25 or 26 will close contact 20 and a following signal on terminal 27 or 26 will open contact 20 again.

Substantially the same sequence of operations can be obtained by substituting a relay for the thyratron as shown in Fig. 2. Here the coil of the relay replaces the grid circuit 23 of the thyratron 24 of Fig. 1 and is connected between terminal 26 and a reference potential, such as ground. The relay carries a normally open set of contacts 411 closed by an operator .2 attached to a core 43 and connected between one side of the contacts 15 and 18 and ground.

The operation of the modification shown in Fig. 2 is similar to that of the preferred embodiment shown in Fig. 1. When a positive signal appears on either terminal 25 or 26, current flows through the coil 40 of the relay and closes the normally open contact 41 to complete the circuit of coil 11) and energizes it as described above. This closes the normally open 16, 17, 1S and 20 contacts as before and readies the circuit for coil 11 While holding coil 10 energized and breaks the normally closed contacts 15 and 16.

For proper operation relay 40 must be sufiicient slow in releasing so that the holding contact 17 is made before contact 15 breaks. However, it cannot be so slow that contact 41 is still closed when contact 18 makes. Adjustments are such that the energizing pulse passes and relay coil 40 becomes deenergized before contacts 13 are made so that the relay coil 11 will not be energized until a second pulse appears at either terminal 26 or 27 to reenergize coil 40 of the added relay. It will be seen that timing adjustments are more critical with this modified circuit and relatively large amounts of triggering energy will be required to operate the added relay. The signals would have to be in the form of pulses of high energy and short duration with respect to the separation of pulses.

The preferred version of Fig. 1 would not be as seriously limited in this respect. The pulses in this preferred version need have less energy and there need be less time between them. The deenergizing time of a thyratron, such as a hydrogen thyratron, is sufficient interval between pulses. The triggering action depends on voltage rather than current so that little energy is needed.

Contact 20 has been shown and described as a single normally open contact. It could be a normally closed contact or any mechanical device adapted to be operated by solenoid action.

This invention is not limited to the particular details of construction, materials and processes described, as many equivalents will suggest themselves to those skilled in the art. It is accordingly desired that the appended claims be given a broad interpretation commensurate with the scope of the invention within the art.

What is claimed is:

1. In combination, a circuit controller, two windings adapted to apply opposing forces to said controller when energized, an energizing path for a first of said windings comprising a set of contacts operated by said controller and closed when both said windings are de-energized and a switching device providing a normally open path, means for connecting said device to a first source of control signals directly, means for connecting said device to a second source of such signals over a set of contacts closed when both said coils are de-energized, means for connecting said device to a third source of such signals over a set of contacts open when both said coils are tie-energized, said last-mentioned two sets of contacts being operated by said controller, a holding current circuit for a first of said windings comprising a set of contacts operated by said controller and open when said windings are de-energized and the normally-open circuit in the said switching device.

2. In combination, a circuit controller, two windings adapted to apply opposing forces to said controller when energized, an energizing path for a first of said windings comprising a set of contacts operated by said controller and closed when both said windings are .de-energized and a switching device providing a normally open path, said switching device comprising a grid-controlled gaseous discharge device, means for connecting the grid of said device to a first source of control signals directly, means for connecting the grid of said device to a second source of such signals over a set of contacts closed when both said coils are de-energized, means for connecting the grid of said device to a third source of such signals over a set of contacts open when both said coils are tie-energized, said last-mentioned two sets of contacts being operated by said controller, a holding current circuit for a first of said windings comprising a set of contacts operated by said controller and open when said windings are de-energized, an energizing circuit for a second of said windings comprising a set of contacts operated by said controller and open when said windings are deenergized and the normally-open circuit in the said switching device.

3. In combination, a circuit controller, two windings adapted to apply opposing forces to said controller when energized, an energizing path for a first of said windings comprising a set of contacts operated by said controller and closed when both said windings are ale-energized and a switching device providing a normally ope P3 11, Said switching device comprising a set of normally open corn tacts controlled by an electro-magnetic device, means for connecting said switch controlling electro magnetic device to a first source of control signals directly, means for connecting said device to a second source of such signals over a set of contacts closed when both said coils are de-energized, means for connecting said device to a third source .of such signals over a set of contacts open when .both said coils are de-energized, said last-mentioned two sets of contacts being operated by said controller, a holding current circuit for a first of said windings comprising a set of contacts operated by said controller and open when said windings are deenergized, an energizing circuit for a second of said windings comprising a setof contacts operated by said controller and open when said windings are tie-energized and the normally-open .circuit in the said switching device.

References Cited in the file of this patent UNITED STATES PATENTS 1,031,096 Steen July 2, 1912 1,845,227 Bower Feb. 16, 1932 1,893,223 Burlde Jan. 3, 1933 1,968,385 Gille July 31 1934 2,181,539 Wertz Nov. 28, 1939 2,306,237 Vlolfner Dec. '12, 1942 2,339,750 Bartholy g Jan. 25, 1944 2,371,931 Few Mar. '20, 1945 2,529,323 Aiken Nov. 7, 1 950 FOREIGN PATENTS 116,625 Australia Mar. 11 1943 

